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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        function Dog(name) {
            this.name = name;
            this.seeDoor =
            this.cry = function () {
                console.log('cry');
            }
        }

        let laifu = new Dog('来福');
        let changwei = new Dog('常威');
        laifu.seeDoor();
        changwei.cry();

    </script>
</body>

</html>